Mineral wool binder

ABSTRACT

The present invention relates to a formaldehyde-free binder composition for mineral fibres comprising: —at least one phenol and/or quinone containing compound, —at least one protein, —at least one fatty acid ester of glycerol.

FIELD OF THE INVENTION

The present invention relates to a mineral wool binder, a method of producing a mineral wool product with the binder and a mineral wool product made with the binder.

BACKGROUND OF THE INVENTION

Mineral fibre products generally comprise man-made vitreous fibres (MMVF) such as, e.g., glass fibres, ceramic fibres, basalt fibres, slag wool, mineral wool and stone wool (rock wool), which are bonded together by a cured thermoset polymeric binder material. For use as thermal or acoustical insulation products, bonded mineral fibre mats are generally produced by converting a melt made of suitable raw materials to fibres in conventional manner, for instance by a spinning cup process or by a cascade rotor process. The fibres are blown into a forming chamber and, while airborne and while still hot, are sprayed with a binder solution and randomly deposited as a mat or web onto a travelling conveyor. The fibre mat is then transferred to a curing oven where heated air is blown through the mat to cure the binder and rigidly bond the mineral fibres together.

In the past, the binder resins of choice have been phenol-formaldehyde resins which can be economically produced and can be extended with urea prior to use as a binder. However, the existing and proposed legislation directed to the lowering or elimination of formaldehyde emissions have led to the development of formaldehyde-free binders such as, for instance, the binder compositions based on polycarboxy polymers and polyols or polyamines, such as disclosed in EP-A-583086, EP-A-990727, EP-A-1741726, U.S. Pat. No. 5,318,990 and US-A-2007/0173588.

Another group of non-phenol-formaldehyde binders are the addition/-elimination reaction products of aliphatic and/or aromatic anhydrides with alkanolamines, e.g., as disclosed in WO 99/36368, WO 01/05725, WO 01/96460, WO 02/06178, WO 2004/007615 and WO 2006/061249. These binder compositions are water soluble and exhibit excellent binding properties in terms of curing speed and curing density. WO 2008/023032 discloses urea-modified binders of that type which provide mineral wool products having reduced moisture take-up.

Since some of the starting materials used in the production of these binders are rather expensive chemicals, there is an ongoing need to provide formaldehyde-free binders which are economically produced.

A further effect in connection with previously known aqueous binder compositions from mineral fibres is that at least the majority of the starting materials used for the productions of these binders stem from fossil fuels. There is an ongoing trend of consumers to prefer products that are fully or at least partly produced from renewable materials and there is therefore a need to provide binders for mineral wool which are at least partly produced from renewable materials.

A further effect in connection with previously known aqueous binder compositions for mineral fibres is that they involve components which are corrosive and/or harmful. This requires protective measures for the machinery involved in the production of mineral wool products to prevent corrosion and also requires safety measures for the persons handling this machinery. This leads to increased costs and health issues and there is therefore a need to provide binder compositions for mineral fibres with a reduced content of corrosive and/or harmful materials.

A yet further effect in connection with previously known aqueous binder compositions from mineral fibres is that these binders are conventionally associated with extensive curing equipment for curing the binder. The curing equipment is conventionally an oven operating at temperatures far above 100° C. such as around 200° C. The oven is several meters long to accommodate the web that is continuously fed into the oven and to ensure that the web is fully cured when leaving the oven. Such oven equipment is associated with extensive energy consumption.

The reference C. Peña, K. de la Caba, A. Eceiza, R. Ruseckaite, I. Mondragon in Biores. Technol. 2010, 101, 6836-6842 is concerned with the replacement of non-biodegradable plastic films by renewable raw materials from plants and wastes of meat industry. In this connection, this reference describes the use of hydrolysable chestnut-tree tannin for modification of a gelatin in order to form films. The reference does not describe binders, in particular not binders for mineral wool.

Mineral wool binders on the basis of renewable materials have been proposed before. While some of these binders show excellent overall properties, there are still some disadvantages of mineral wool products prepared with these binders in terms of strength and water absorption when compared with mineral wool products prepared with phenol-formaldehyde resins.

SUMMARY OF THE INVENTION

Accordingly, it was an object of the present invention to provide a binder composition which is particularly suitable for bonding mineral fibres, uses renewable materials as starting materials, reduces or eliminates corrosive and/or harmful materials, and at the same time allow the preparation of mineral wool products having excellent strength properties and a low water absorption.

Further, it was an object of the present invention to provide a binder composition which does not require high temperature for curing and therefore eliminates need of high temperature to be applied in the production of a product bonded with the binder composition.

A further object of the present invention was to provide a mineral wool product bonded with such a binder composition.

A further object of the present invention was to provide a method of making such mineral wool product.

A further object of the present invention was to provide the use of such a binder composition for the preparation of the mineral wool product.

In accordance with a first aspect of the present invention, there is provided a, preferably formaldehyde-free, binder composition for mineral fibres comprising:

-   -   at least one phenol and/or quinone containing compound,     -   at least one protein,     -   at least one fatty acid ester of glycerol.

In accordance with a second aspect of the present invention, there is provided a mineral wool product comprising mineral fibres bound by a binder resulting from the curing of such a binder composition.

In accordance with a third aspect of the present invention, there is provided a method of producing a mineral wool product which comprises the steps of contacting mineral fibres with such a binder composition.

In accordance with a fourth aspect of the present invention, there is provided the use of such a binder composition for the preparation of the mineral wool product.

The present inventors have surprisingly found that it is possible to obtain a mineral wool product having excellent strength properties and low water absorption comprising mineral fibres bound by a binder resulting from the curing of a binder composition, whereby the binder composition can be produced from renewable materials to a large degree, does not contain, or contains only to a minor degree, any corrosive and/or harmful agents and the production of the mineral wool product does not lead to pollution such as VOC's (Volatile Organic Compounds) during the preparation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The binder composition according to the present invention comprises:

-   -   at least one phenol and/or quinone containing compound,     -   at least one protein,     -   at least one fatty acid ester of glycerol.

In a preferred embodiment, the binders according to the present invention are formaldehyde free.

For the purpose of the present application, the term “formaldehyde free” is defined to characterize a mineral wool product where the emission is below 5 μg/m²/h of formaldehyde from the mineral wool product, preferably below 3 μg/m²/h. Preferably, the test is carried out in accordance with ISO 16000 for testing aldehyde emissions.

A surprising advantage of embodiments of mineral wool products according to the present invention is that they show self-healing properties. After being exposed to very harsh conditions when mineral wool products loose a part of their strength, the mineral wool products according to the present invention can regain a part of the original strength. This is in contrast to conventional mineral wool products for which the loss of strength after being exposed to harsh environmental conditions is irreversible. While not wanting to be bound to any particular theory, the present inventors believe that this surprising property in mineral wool products according to the present invention is due to the complex nature of the bonds formed in the network of the protein crosslinked by the phenol and/or quinone containing compound which also includes quaternary structures and hydrogen bonds and allows bonds in the network to be established after returning to normal environmental conditions. For an insulation product, which when e.g. used as a roof insulation can be exposed to very high temperatures in the summer, this is an important advantage for the long term stability of the product.

Phenol and/or Quinone Containing Compound Component of the Binder

The binder composition according to the present invention comprises a phenol and/or quinone containing compound component of the binder, in particular one or more phenolic compound and/or one or more quinone.

Phenolic compounds, or phenolics, are compounds that have one or more hydroxyl group attached directly to an aromatic ring. Polyphenols (or polyhydroxyphenols) are compounds that have more than one phenolic hydroxyl group attached to one or more aromatic rings. Phenolic compounds are characteristic of plants and as a group they are usually found as esters or glycosides rather than as free compounds.

The term phenolics covers a very large and diverse group of chemical compounds. Preferably, the phenol containing compound is a compound according to the scheme based on the number of carbons in the molecule as detailed in by W. Vermerris, R. Nicholson, in Phenolic Compound Biochemistry, Springer Netherlands, 2008.

Preferably, the phenol containing compound is in form of one or more components selected from the group consisting of a compound with a C₆ structure such as simple phenolics, such as resorcinol, phloroglucinol, such as a compound with a C₆-C₁ structure such as hydroxybenzoic acids, such as p-hydroxybenzoic acid, gallic acid, protocathechuic acid, salicylic acid, vanillic acid, such as hydroxybenzoic aldehydes, such as vanillin, such as a compound with a C₆-C₂ structure such as hydroxyacetophenones, such as 2-hydroxyacetophenone, such as hydroxyphenylacetic acids, such as 2-hydroxyphenyl acetic acid, such as a compound with a C₆-C₃ structure such as cinnamic acids, such as p-coumaric acid, caffeic acid, ferulic acid, 5-hydroxyferulic acid, sinapic acid, such as cinnamic acid esters, such as chlorogenic acid, sinapoyl malate, sinapoyl choline, such as cinnamyl aldehydes, such as cinnamyl alcohols, such as coumarins, such as umbelliferone, 4-methyl umbelliferone, such as isocoumarins, such as bergenin, such as chromones, such as a compound with a C₁₅ structure such as flavonoids, such as flavanone, isoflavones, isoflavanones, neoflavanoids, such as chalcones, such as butein, such as dihydrochalcones, such as phloridzin, such as aurones, such as flavanones, such as naringenin, such as flavanonols, such as taxifolin, such as flavans, such as leucoanthocyanidins, such as leucocyanidin, leucodelphinidin, such as flavan-3-ols, such as catechin, gallocatechin, such as flavones, such as kaemferol, quercetin, myricetin, such as anthocyanidins, such as pelargonidin, cyanidin, peonidin, delphinidin, petunidin, malvidin, such as deoxyanthocyanidines, such as apigeninidin, luteolinidin, 7-methoxyapigeninidin, 5-methoxy-luteolinidin, such as anthocyanins, such as petanin, such as a compound with a C₃₀ structure such as biflavonyls, such as ginkgetin, such as a compound with a C₆-C₁-C₆ structure such as benzophenones, such as xanthones, such as a compound with a C₆-C₂-C₆ structure such as stilbenes, such as resveratrol, pinosylvin, such as a compound with a C₆/C₁₀/C₁₄ structure such as benzoquinones, such as naphthaquinones, such as juglone, such as anthraquinones, such as emodin, such as a compound with a C₁₈ structure such as betacyanins, such as betanidin, such as polyphenols and/or polyhydroxyphenols, such as lignans, neolignans (dimers or oligomers from coupling of monolignols such as p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol), such as pinoresinol, sesamin, plicatic acid, such as lignins (synthesized primarily from the monolignol precursors p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol), such as tannins, such as condensed tannins (proanthocyanidins), such as procyanidin B₂, such as hydrolysable tannins, such as gallotannins, such as ellagitannins, such as complex tannins, such as acutissimin A, such as tannic acid, such as phlobabenes.

In a preferred embodiment, the phenol containing compound is selected from the group consisting of simple phenolics, phenol containing compounds with a more complex structure than a C₆ structure, such as oligomers of simple phenolics, polyphenols, and/or polyhydroxyphenols.

Quinones are oxidized derivatives of aromatic compounds and are often readily made from reactive aromatic compounds with electron-donating substituents such as phenolics. Quinones useful for the present invention include benzoquinones, napthoquinone, anthraquinone and lawsone.

The phenol and/or quinone containing compounds according to the present invention can also be synthetic or semisynthetic molecules or constructs that contain phenols, polyphenols and/or quinones. An example for such a construct is a protein, peptide, peptoids (such as linear and/or cyclic oligomers and/or polymers of N-substituted glycines, N-substituted β-alanines), arylopeptoids (such as linear and/or cyclic oligomers and/or polymers of N-substituted aminomethyl benzamides), polystyrenes modified with phenol and/or quinone containing side chains. A dendrimer decorated with phenol and/or quinone containing side chains is another example.

Tannins comprise a group of compounds with a wide diversity in structure that share their ability to bind and precipitate proteins. Tannins are abundant in many different plant species, in particular oak, chestnut, staghorn sumac and fringe cups. Tannins can be present in the leaves, bark and fruits. Tannins can be classified into three groups: condensed tannins, hydrolysable tannins and complex tannins. Condensed tannins, or proanthocyanidins, are oligomeric or polymeric flavonoids consisting of flavan-3-ol (catechin) units. Gallotannins are hydrolysable tannins with a polyol core substituted with 10-12 gallic acid residues. The most commonly found polyol in gallotannins is D-glucose although some gallotannins contain catechin and triterpenoid units as the core polyol. Ellagitanins are hydrolysable tannins that differ from gallotannins in that they contain additional C—C bonds between adjacent galloyl moieties. Complex tannins are defined as tannins in which a catechin unit is bound glycosidically to either a gallotannin or an ellagitannin unit.

The inventors have surprisingly found that a wide range of such phenol and/or quinone containing compounds can be used to crosslink proteins which allows a binder composition to be formed. Often, these phenol and/or quinone containing compound components are obtained from vegetable tissues and are therefore a renewable material. In some embodiments, the compounds are also non-toxic and non-corrosive. As a further advantage, these compounds are antimicrobial and therefore impart their antimicrobial properties to the mineral wool product bound by such a binder.

In a preferred embodiment, the phenol and/or quinone containing compound is selected from one or more components from the group consisting of tannic acid, ellagitannins and gallotannins, tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups.

Protein Component of the Binder

Preferably, the protein component of the binder is in form of one or more proteins selected from the group consisting of proteins from animal sources, including collagen, gelatin, hydrolysed gelatin, and protein from milk (casein, whey), eggs; proteins from vegetable sources, including proteins from legumes, cereals, whole grains, nuts, seeds and fruits, like protein from buckwheat, oats, rye, millet, maize (corn), rice, wheat, bulgur, sorghum, amaranth, quinoa, soybeans (soy protein), lentils, kidney beans, white beans, mung beans, chickpeas, cowpeas, lima beans, pigeon peas, lupines, wing beans, almonds, Brazil nuts, cashews, pecans, walnuts, cotton seeds, pumpkin seeds, hemp seeds, sesame seeds, and sunflower seeds; polyphenolic proteins such as mussel foot protein.

Collagen is a very abundant material in living tissue: It is the main component in connective tissue and constitutes 25-35% of the total protein content in mammals. Gelatin is derived from chemical degradation of collagen. Gelatin may also be produced by recombinant techniques. Gelatin is water soluble and has a molecular weight of 10.000 to 500.000 g/mol, such as 30.000 to 300.000 g/mol dependent on the grade of hydrolysis. Gelatin is a widely used food product and it is therefore generally accepted that this compound is totally non-toxic and therefore no precautions are to be taken when handling gelatin.

Gelatin is a heterogeneous mixture of single or multi-stranded polypeptides, typically showing helix structures. Specifically, the triple helix of type I collagen extracted from skin and bones, as a source for gelatin, is composed of two α1(I) and one α2(I) chains.

Gelatin solutions may undergo coil-helix transitions.

A type gelatins are produced by acidic treatment. B type gelatins are produced by basic treatment.

Chemical cross-links may be introduced to gelatin. In one embodiment, transglutaminase is used to link lysine to glutamine residues; in one embodiment, glutaraldehyde is used to link lysine to lysine, in one embodiment, tannins are used to link lysine residues.

The gelatin can also be further hydrolysed to smaller fragments of down to 3000 g/mol.

On cooling a gelatin solution, collagen like helices may be formed.

Gelatin may form helix structures.

In one embodiment, the cured binder comprising protein comprises helix structures.

In one embodiment, the at least one protein is a low strength gelatin, such as a gelatin having a gel strength of 30 to 125 Bloom.

In one embodiment, the at least one protein is a medium strength gelatin, such as a gelatin having a gel strength of 125 to 180 Bloom.

In one embodiment, the at least one protein is a high strength gelatin, such as a gelatin having a gel strength of 180 to 300 Bloom.

In a preferred embodiment, the gelatin is preferably originating from one or more sources from the group consisting of mammal, bird species, such as from cow, pig, horse, fowl, and/or from scales, skin of fish.

In one embodiment, urea may be added to the binder compositions according to the present invention. The inventors have found that the addition of even small amounts of urea causes denaturation of the gelatin, which can slow down the gelling, which might be desired in some embodiments. The addition of urea might also lead to a softening of the product.

The inventors have found that the carboxylic acid groups in gelatins interact strongly with trivalent and tetravalent ions, for example aluminum salts. This is especially true for type B gelatins which contain more carboxylic acid groups than type A gelatins.

The present inventors have found that in some embodiments, curing/drying of binder compositions according to the present invention including gelatin should not start off at very high temperatures.

The inventors have found that starting the curing at low temperatures may lead to stronger products. Without being bound to any particular theory, it is assumed by the inventors that starting curing at high temperatures may lead to an impenetrable outer shell of the binder composition which hinders water from underneath to get out.

Surprisingly, the binders according to the present invention including gelatins are very heat resistant. The present inventors have found that in some embodiments the cured binders can sustain temperatures up to 300° C. without degradation.

Fatty Acid Ester of Glycerol

The binder composition according to the present invention comprises a component in form of at least one fatty acid ester of glycerol.

A fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated.

Glycerol is a polyol compound having the IUPAC name propane-1,2,3-triol.

Naturally occurring fats and oils are glycerol esters with fatty acids (also called triglycerides).

For the purpose of the present invention, the term fatty acid ester of glycerol refers to mono-, di-, and tri-esters of glycerol with fatty acids.

While the term fatty acid can in the context of the present invention be any carboxylic acid with an aliphatic chain, it is preferred that it is carboxylic acid with an aliphatic chain having 4 to 28 carbon atoms, preferably of an even number of carbon atoms. Preferably, the aliphatic chain of the fatty acid is unbranched.

In a preferred embodiment, the at least one fatty acid ester of glycerol is in form of a plant oil and/or animal oil. In the context of the present invention, the term “oil” comprises at least one fatty acid ester of glycerol in the form of oils or fats.

In a preferred embodiment, the at least one fatty acid ester of glycerol is a plant-based oil.

In a preferred embodiment, the at least one fatty acid ester of glycerol is in form of fruit pulp fats such as palm oil, olive oil, avocado oil; seed-kernel fats such as lauric acid oils, such as coconut oil, palm kernel oil, babassu oil and other palm seed oils, other sources of lauric acid oils; palmitic-stearic acid oils such as cocoa butter, shea butter, borneo tallow and related fats (vegetable butters); palmitic acid oils such as cottonseed oil, kapok and related oils, pumpkin seed oil, corn (maize) oil, cereal oils; oleic-linoleic acid oils such as sunflower oil, sesame oil, linseed oil, perilla oil, hempseed oil, teaseed oil, safflower and niger seed oils, grape-seed oil, poppyseed oil, leguminous oil such as soybean oil, peanut oil, lupine oil; cruciferous oils such as rapeseed oil, mustard seed oil; conjugated acid oils such as tung oil and related oils, oiticica oil and related oils; substituted fatty acid oils such as castor oil, chaulmoogra, hydnocarpus and gorli oils, vernonia oil; animal fats such as land-animal fats such as lard, beef tallow, mutton tallow, horse fat, goose fat, chicken fat; marine oils such as whale oil and fish oil.

In a preferred embodiment, the at least one fatty acid ester of glycerol is in form of a plant oil, in particular selected from one or more components from the group consisting of linseed oil, olive oil, tung oil, coconut oil, hemp oil, rapeseed oil, and sunflower oil.

In a preferred embodiment, the at least one fatty acid ester of glycerol is selected from one or more components from the group consisting of a plant oil having an iodine number in the range of approximately 136 to 178, such as a linseed oil having an iodine number in the range of approximately 136 to 178, a plant oil having an iodine number in the range of approximately 80 to 88, such as an olive oil having an iodine number in the range of approximately 80 to 88, a plant oil having an iodine number in the range of approximately 163 to 173, such as tung oil having an iodine number in the range of approximately 163 to 173, a plant oil having an iodine number in the range of approximately 7 to 10, such as coconut oil having an iodine number in the range of approximately 7 to 10, a plant oil having an iodine number in the range of approximately 140 to 170, such as hemp oil having an iodine number in the range of approximately 140 to 170, a plant oil having an iodine number in the range of approximately 94 to 120, such as a rapeseed oil having an iodine number in the range of approximately 94 to 120, a plant oil having an iodine number in the range of approximately 118 to 144, such as a sunflower oil having an iodine number in the range of approximately 118 to 144.

In one embodiment, the at least one fatty acid ester of glycerol is not of natural origin.

In one embodiment, the at least one fatty acid ester of glycerol is a modified plant or animal oil.

In one embodiment, the at least one fatty acid ester of glycerol comprises at least one trans-fatty acid.

In an alternative preferred embodiment, the at least one fatty acid ester of glycerol is in form of an animal oil, such as a fish oil.

In one embodiment, the binder results from the curing of a binder composition comprising gelatin, and wherein the binder composition further comprises a tannin selected from one or more components from the group consisting of tannic acid, condensed tannins (proanthocyanidins), hydrolysable tannins, gallotannins, ellagitannins, complex tannins, and/or tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups, preferably tannic acid, and the binder composition further comprises at least one fatty acid ester of glycerol, such as at least one fatty acid ester of glycerol selected from one or more components from the group consisting of linseed oil, olive oil, tung oil, coconut oil, hemp oil, rapeseed oil, and sunflower oil.

The present inventors have found that the parameter for the fatty acid ester of glycerol used in the binders according to the present invention of the amount of unsaturation in the fatty acid can be used to distinguish preferred embodiments.

The amount of unsaturation in fatty acids is usually measured by the iodine number (also called iodine value or iodine absorption value or iodine index). The higher the iodine number, the more C═C bonds are present in the fatty acid. For the determination of the iodine number as a measure of the unsaturation of fatty acids, we make reference to Thomas, Alfred (2012) “Fats and fatty oils” in Ullmann's Encyclopedia of industrial chemistry, Weinheim, Wiley-VCH.

In a preferred embodiment, the at least one fatty acid ester of glycerol comprises a plant oil and/or animal oil having a iodine number of ≥75, such as 75 to 180, such as ≥130, such as 130 to 180.

In an alternative preferred embodiment, the at least one fatty acid ester of glycerol comprises a plant oil and/or animal oil having a iodine number of ≤100, such as ≤25.

In one embodiment, the at least one fatty acid ester of glycerol is a drying oil. For a definition of a drying oil, see Poth, Ulrich (2012) “Drying oils and related products” in Ullmann's Encyclopedia of industrial chemistry, Weinheim, Wiley-VCH.

Accordingly, the present inventors have found that particularly good results are achieved when the iodine number is either in a fairly high range or, alternatively, in a fairly low range. While not wanting to be bound by any particular theory, the present inventors assume that the advantageous properties inflicted by the fatty acid esters of high iodine number on the one hand and low iodine number on the other hand are based on different mechanisms. The present inventors assume that the advantageous properties of glycerol esters of fatty acids having a high iodine number might be due to the participation of the C═C double-bonds found in high numbers in these fatty acids in a crosslinking reaction, while the glycerol esters of fatty acids having a low iodine number and lacking high amounts of C═C double-bonds might allow a stabilization of the cured binder by van der Waals interactions. The present inventors assume that the polar end of glycerol esters of fatty acids interacts with polar areas of the at least one protein while non-polar ends interact with non-polar areas of the at least one protein.

Reaction of the Binder Components

Without wanting to be bound to any particular theory, the present inventors believe that the reaction between the phenol and/or quinone containing compound and the protein at least partly relies on a oxidation of phenols to quinones followed by nucleophilic attack of amine and/or thiol groups from the protein which leads to a crosslinking of the proteins by the phenol and/or quinone containing compounds.

In a preferred embodiment, the content of the phenol and/or quinone containing compound in the binder composition according to the present invention is from 1 to 70 wt. %, such as 2 to 60 wt. %, such as 3 to 50 wt. %, such as 4 to 40 wt. %, such as 5 to 35 wt. %, based on dry protein basis.

In an alternative preferred embodiment, the mass ratio of (lysine+cystein) in the protein to (phenol+quinone) in the phenol and/or quinone containing compound is 1:5.78-1:0.08, such as 1:2.89-1:0.09, such as 1:1.93-1:0.12, such as 1:1.45-1:0.15, such as 1:1.16-1:0.17.

The term mass ratio of (lysine+cystein) in the protein to (phenol+quinone) in the phenol and/or quinone containing compound is to be understood to mean the ratio of the combined mass of the lysine+cystein residues in the proteine component to the combined mass of the phenol+quinone residues in the phenol and/or quinone containing compound.

In a preferred embodiment, the content of the fatty acid ester of glycerol is 0.5 to 40, such as 1 to 30, such as 1.5 to 20, such as 3 to 10, such as 4 to 7.5 wt.-%, based on dry protein basis.

The present inventors have found that the curing of the binder is strongly accelerated under alkaline conditions. Therefore, in one embodiment, the binder composition for mineral fibres comprises a pH-adjuster, preferably in form of a base, such as organic base, such as amine or salts thereof, inorganic bases, such as metal hydroxide, such as KOH or NaOH, ammonia or salts thereof.

In a particular preferred embodiment, the pH adjuster is an alkaline metal hydroxide, in particular NaOH.

In a preferred embodiment, the binder composition according to the present invention has a pH of 7 to 10, such as 7.5 to 9.5, such as 8 to 9.

In one embodiment, the protein comprises polyphenolic proteins.

These proteins contain a high level of a post-translationally modified-oxidized-form of tyrosine, L-3,4-dihydroxyphenylalanine (levodopa, L-DOPA). See also J. J. Wilker Nature Chem. Biol. 2011, 7, 579-580 for a reference to these proteins.

Additives

In one embodiment, the at least one anti-fouling agent is an antimicrobial agent.

Antimicrobial agents may be benzoic acid, propionic acid, sodium benzoate, sorbic acid, and potassium sorbate to inhibit the outgrowth of both bacterial and fungal cells. However, natural biopreservatives may be used. Chitosan is regarded as being antifungal and antibacterial. The most frequently used biopreservatives for antimicrobial are lysozyme and nisin. Common other biopreservatives that may be used are bacteriocins, such as lacticin and pediocin and antimicrobial enzymes, such as chitinase and glucose oxidase. Also, the use of the enzyme lactoperoxidase (LPS) presents antifungal and antiviral activities. Natural antimicrobial agents may also be used, such as tannins, rosemary, and garlic essential oils, oregano, lemon grass, or cinnamon oil at different concentrations.

In a preferred embodiment, the binder composition according to the present invention contains additives.

Other additives may be components such as one or more reactive or nonreactive silicones and may be added to the binder. Preferably, the one or more reactive or nonreactive silicone is selected from the group consisting of silicone constituted of a main chain composed of organosiloxane residues, especially diphenylsiloxane residues, alkylsiloxane residues, preferably dimethylsiloxane residues, bearing at least one hydroxyl, acyl, carboxyl or anhydride, amine, epoxy or vinyl functional group capable of reacting with at least one of the constituents of the binder composition and is preferably present in an amount of 0.1-15 weight-%, preferably from 0.1-10 weight-%, more preferably 0.3-8 weight-%, based on the total binder mass.

In one embodiment, an emulsified hydrocarbon oil may be added to the binder.

As already described above, many phenol and/or quinone containing compounds, in particular polyphenols, have antimicrobial properties and therefore impart antimicrobial characteristic to the binder. Nevertheless, in one embodiment, an anti-fouling agent may be added to the binder compositions.

In one embodiment, an anti-swelling agent may be added to the binder, such as tannic acid and/or tannins.

In one embodiment, the binder composition according to the present invention contains additives in form of amine linkers and/or thiol/thiolate linkers. These additives in form of amine linkers and/or thiol/thiolate linkers are particular useful when the crosslinking reaction of the binder proceeds via the quinone-amine and/or quinone-thiol pathway.

In one embodiment, the binder compositions according to the present invention comprise an additive containing metal ions, such as iron ions.

Polyphenolic proteins such as the mussel adhesive protein discussed above relies on 3,4-dihydroxyphenyl moieties to enhance the surface adhesion. This is achieved in combination with the secretion of selected types of cations such as iron ions. In one embodiment, the binder could be said to mimic the polyphenolic protein and therefore the addition of various cations could improve the binder characteristics. Such advantageous ions can also be released from the mineral fibre surface when they come into contact with the aqueous binder.

In one embodiment, the mineral wool product comprises rock wool. Without being bound by theory, it is believed that leaching of certain ions from the vitreous fibres may assist the binding strength. The mechanism may be analogue to the mechanism for which mussel adhesive protein obtains a surface adhesion. This is achieved in combination with the secretion of selected types of cations such as iron ions.

In one embodiment, the binder compositions according to the present invention contain further additives in form of additives selected from the group consisting of PEG-type reagents, silanes, and hydroxylapatites.

Oxidising agents as additives can serve to increase the oxidising rate of the phenolics. One example is the enzyme tyrosinase which oxidizes phenols to hydroxyphenols/quinones and therefore accelerates the binder forming reaction.

In another embodiment, the oxidising agent is oxygen, which is supplied to the binder.

In one embodiment, the curing is performed in oxygen-enriched surroundings.

A Mineral Wool Product Comprising Mineral Wool Fibres Bound by a Binder

The present invention is also directed to a mineral wool product bound by a binder resulting from the curing of the binder composition described.

In a preferred embodiment, the density of the mineral wool product is in the range of 10-1200 kg/m³, such as 30-800 kg/m³, such as 40-600 kg/m³, such as 50-250 kg/m³, such as 60-200 kg/m³.

In a preferred embodiment, the mineral wool product according to the present invention is an insulation product, in particular having a density of 10 to 200 kg/m³.

In an alternative embodiment, the mineral wool product according to the present invention is a facade panel, in particular having a density of approximately 1200 kg/m³.

In a preferred embodiment, the mineral wool product according to the present invention is an insulation product.

In a preferred embodiment, the loss on ignition (LOI) of the mineral wool product according to the present invention is within the range of 0.1 to 25.0%, such as 0.3 to 18.0%, such as 0.5 to 12.0%, such as 0.7 to 8.0% by weight.

In one embodiment the mineral wool product is a mineral wool insulation product, such as a mineral wool thermal or acoustical insulation product.

In one embodiment the mineral wool product is a horticultural growing media.

Method of Producing a Mineral Wool Product

The present invention also provides a method for producing a mineral wool product by binding mineral fibres with the binder composition.

A particular advantage of the mineral wool product according to the present invention is that it does not require high temperatures for curing. This does not only save energy, reduces VOC and obviates the need for machinery to be highly temperature resistant, but also allows for a high flexibility in a process for the production of mineral wool products with these binders.

In one embodiment the method comprises the steps of:

-   -   making a melt of raw materials,     -   fibrerising the melt by means of a fiber forming apparatus to         form mineral fibres,     -   providing the mineral fibres in the form of a collected web,     -   mixing the binder with the mineral fibres before, during or         after the provision of the collected web to form a mixture of         mineral fibres and binder,     -   curing the mixture of mineral fibres and binder.

In one embodiment, the binder is supplied in the close vicinity of the fibre forming apparatus, such as a cup spinning apparatus or a cascade spinning apparatus, in either case immediately after the fibre formation. The fibres with applied binder are thereafter conveyed onto a conveyor belt as a web.

The web may be subjected to longitudinal or length compression after the fibre formation and before substantial curing has taken place.

Fiber Forming Apparatus

There are various types of centrifugal spinners for fiberising mineral melts.

A conventional centrifugal spinner is a cascade spinner which comprises a sequence of a top (or first) rotor and a subsequent (or second) rotor and optionally other subsequent rotors (such as third and fourth rotors). Each rotor rotates about a different substantially horizontal axis with a rotational direction opposite to the rotational direction of the or each adjacent rotor in the sequence. The different horizontal axes are arranged such that melt which is poured on to the top rotor is thrown in sequence on to the peripheral surface of the or each subsequent rotor, and fibres are thrown off the or each subsequent rotor, and optionally also off the top rotor.

In one embodiment, a cascade spinner or other spinner is arranged to fiberise the melt and the fibres are entrained in air as a cloud of the fibres.

Many fiber forming apparatuses comprise a disc or cup that spins around a substantially vertical axis. It is then conventional to arrange several of these spinners in-line, i.e. substantially in the first direction, for instance as described in GB-A-926,749, U.S. Pat. No. 3,824,086 and WO-A-83/03092.

There is usually a stream of air associated with the one or each fiberising rotor whereby the fibres are entrained in this air as they are formed off the surface of the rotor.

In one embodiment, binder and/or additives is added to the cloud of fibres by known means. The amount of binder and/or additive may be the same for each spinner or it may be different.

In one embodiment, a hydrocarbon oil (mineral oil) may be added into the cloud of fibres.

As used herein, the term “collected web” is intended to include any mineral fibres that have been collected together on a surface, i.e. they are no longer entrained in air, e.g. the fibrerised mineral fibres, granulate, tufts or recycled web waste. The collected web could be a primary web that has been formed by collection of fibres on a conveyor belt and provided as a starting material without having been cross-lapped or otherwise consolidated.

Alternatively, the collected web could be a secondary web that has been formed by crosslapping or otherwise consolidating a primary web. Preferably, the collected web is a primary web.

In one embodiment the mixing of the binder with the mineral fibres is done after the provision of the collected web in the following steps:

-   -   subjecting the collected web of mineral fibres to a         disentanglement process,     -   suspending the mineral fibres in a primary air flow,     -   mixing binder composition with the mineral fibres before, during         or after the disentanglement process to form a mixture of         mineral fibres and binder.

A method of producing a mineral wool product comprising the process step of disentanglement is described in EP10190521, which is incorporated by reference.

In one embodiment, the disentanglement process comprises feeding the collected web of mineral fibres from a duct with a lower relative air flow to a duct with a higher relative air flow. In this embodiment, the disentanglement is believed to occur, because the fibres that enter the duct with the higher relative air flow first are dragged away from the subsequent fibres in the web. This type of disentanglement is particularly effective for producing open tufts of fibres, rather than the compacted lumps that can result in an uneven distribution of materials in the product.

According to a particularly preferred embodiment, the disentanglement process comprises feeding the collected web to at least one roller which rotates about its longitudinal axis and has spikes protruding from its circumferential surface. In this embodiment, the rotating roller will usually also contribute at least in part to the higher relative air flow. Often, rotation of the roller is the sole source of the higher relative air flow.

In preferred embodiments, the mineral fibres and optionally the binder are fed to the roller from above. It is also preferred for the disentangled mineral fibres and optionally the binder to be thrown away from the roller laterally from the lower part of its circumference. In the most preferred embodiment, the mineral fibres are carried approximately 180 degrees by the roller before being thrown off.

The binder may be mixed with the mineral fibres before, during or after the disentanglement process. In some embodiments, it is preferred to mix the binder with the fibres prior to the disentanglement process. In particular, the fibres can be in the form of an uncured collected web containing binder.

It is also feasible that the binder be pre-mixed with a collected web of mineral fibres before the disentanglement process. Further mixing could occur during and after the disentanglement process. Alternatively, it could be supplied to the primary air flow separately and mixed in the primary air flow.

The mixture of mineral fibres and binder is collected from the primary air flow by any suitable means. In one embodiment, the primary air flow is directed into the top of a cyclone chamber, which is open at its lower end and the mixture is collected from the lower end of the cyclone chamber.

The mixture of mineral fibres and binder is preferably thrown from the disentanglement process into a forming chamber.

Having undergone the disentanglement process, the mixture of mineral fibres and binder is collected, pressed and cured. Preferably, the mixture is collected on a foraminous conveyor belt having suction means positioned below it.

In a preferred method according to the invention, the mixture of binder and mineral fibres, having been collected, is pressed and cured.

In a preferred method according to the invention, the mixture of binder and mineral fibres, having been collected, is scalped before being pressed and cured.

The method may be performed as a batch process, however according to an embodiment the method is performed at a mineral wool production line feeding a primary or secondary mineral wool web into the fibre separating process, which provides a particularly cost efficient and versatile method to provide composites having favourable mechanical properties and thermal insulation properties in a wide range of densities.

At the same time, because of the curing at ambient temperature, the likelihood of uncured binder spots is strongly decreased.

Curing

The web is cured by a chemical and/or physical reaction of the binder components.

In one embodiment, the curing takes place in a curing device.

In one embodiment the curing is carried out at temperatures from 5 to 95° C., such as 10 to 60° C., such as 20 to 40° C.

The curing process may commence immediately after application of the binder to the fibres. The curing is defined as a process whereby the binder composition undergoes a chemical reaction which usually increases the molecular weight of the compounds in the binder composition and thereby increases the viscosity of the binder composition, usually until the binder composition reaches a solid state.

In one embodiment the curing process comprises cross-linking and/or water inclusion as crystal water.

In one embodiment the cured binder contains crystal water that may decrease in content and raise in content depending on the prevailing conditions of temperature, pressure and humidity.

In one embodiment the curing takes place in a conventional curing oven for mineral wool production operating at a temperature of from 5 to 95° C., such as 10 to 60° C., such as 20 to 40° C.

In one embodiment the curing process comprises a drying process, in particular by blowing air or gas over/through the mineral wool product or by increasing temperature.

In a preferred embodiment, the curing of the binder in contact with the mineral fibers takes place in a heat press.

The curing of a binder in contact with the mineral fibers in a heat press has the particular advantage that it enables the production of high-density products.

In one embodiment the curing process comprises drying by pressure. The pressure may be applied by blowing air or gas to the mixture of mineral fibres and binder. The blowing process may be accompanied by heating or cooling or it may be at ambient temperature.

In one embodiment the curing process takes place in a humid environment.

The humid environment may have a relative humidity RH of 60-99%, such as 70-95%, such as 80-92%. The curing in a humid environment may be followed by curing or drying to obtain a state of the prevalent humidity.

The mineral wool product can be in any conventional configuration, for instance a mat or slab, and can be cut and/or shaped (e.g. into pipe sections) before, during or after curing of the binder.

Advantages of the Binder Composition

The mineral wool product according to the present invention has the surprising advantage that it can be produced by a very simple binder which requires as little as only three components, namely at least one protein at least one phenol and/or quinone containing compound, and at least one fatty acid ester of glycerol. The mineral wool product according to the present invention is therefore produced from natural and non-toxic components and is therefore safe to work with. At the same time, the mineral wool product according to the present invention is produced from a binder based on renewable resources, and has excellent properties concerning strength (both unaged and aged) and low water absorption.

A further advantage is the possibility of curing at ambient temperature or in the vicinity of ambient temperature. This not only leads to savings of energy consumption and less complexity of the machinery required but also decreases the likelihood of uncured binder spots, which can occur during thermal curing of conventional binders.

A further advantage is the strongly reduced punking risk.

Punking may be associated with exothermic reactions during manufacturing of the mineral wool product which increase temperatures through the thickness of the insulation causing a fusing or devitrification of the mineral fibres and eventually creating a fire hazard. In the worst case, punking causes fires in the stacked pallets stored in warehouses or during transportation.

Yet another advantage is the absence of emissions during curing, in particular the absence of VOC emissions.

Further important advantages are the self-repair capacities of mineral wool products produced from the binders.

A further advantage of the mineral wool products produced with the binder according to the present invention is that they may be shaped as desired after application of the binder but prior to curing. This opens the possibility for making tailor-made products, like pipe sections.

EXAMPLES

In the following examples, several binders which fall under the definition of the present invention were prepared and compared to binders according to the prior art.

Test Methods for Binder Compositions According to the Prior Art

The following properties were determined for the binders according the prior art.

Reagents

Silane (Momentive VS-142) was supplied by Momentive and was calculated as 100% for simplicity. All other components were supplied in high purity by Sigma-Aldrich and were assumed anhydrous for simplicity unless stated otherwise.

Binder Component Solids Content—Definition

The content of each of the components in a given binder solution before curing is based on the anhydrous mass of the components. The following formula can be used:

${{Binder}\mspace{14mu} {component}\mspace{14mu} {solids}\mspace{14mu} {content}\mspace{14mu} (\%)} = {\frac{\begin{matrix} {{{binder}\mspace{14mu} {component}\mspace{14mu} A\mspace{14mu} {solids}\mspace{14mu} (g)} +} \\ {{{binder}\mspace{14mu} {component}\mspace{14mu} B\mspace{14mu} {solids}\mspace{14mu} (g)} + \ldots} \end{matrix}}{{total}\mspace{14mu} {weight}\mspace{14mu} {of}\mspace{14mu} {mixture}\mspace{14mu} (g)} \times 100\%}$

Binder Solids—Definition and Procedure

The content of binder after curing is termed “binder solids”.

Disc-shaped stone wool samples (diameter: 5 cm; height 1 cm) were cut out of stone wool and heat-treated at 580° C. for at least 30 minutes to remove all organics. The solids of the binder mixture (see below for mixing examples) were measured by distributing a sample of the binder mixture (approx. 2 g) onto a heat treated stone wool disc in a tin foil container. The weight of the tin foil container containing the stone wool disc was weighed before and directly after addition of the binder mixture. Two such binder mixture loaded stone wool discs in tin foil containers were produced and they were then heated at 200° C. for 1 hour. After cooling and storing at room temperature for 10 minutes, the samples were weighed and the binder solids were calculated as an average of the two results. A binder with the desired binder solids could then be produced by diluting with the required amount of water and 10% aq. silane (Momentive VS-142).

Reaction Loss—Definition

The reaction loss is defined as the difference between the binder component solids content and the binder solids.

Mechanical Strength Studies (Bar Tests)—Procedure

The mechanical strength of the binders was tested in a bar test. For each binder, 16 bars were manufactured from a mixture of the binder and stone wool shots from the stone wool spinning production. The shots are particles which have the same melt composition as the stone wool fibers, and the shots are normally considered a waste product from the spinning process. The shots used for the bar composition have a size of 0.25-0.50 mm.

A 15% binder solids binder solution containing 0.5% silane (Momentive VS-142) of binder solids was obtained as described above under “binder solids”. A sample of this binder solution (16.0 g) was mixed well with shots (80.0 g). The resulting mixture was then filled into four slots in a heat resistant silicone form for making small bars (4×5 slots per form; slot top dimension: length=5.6 cm, width=2.5 cm; slot bottom dimension: length=5.3 cm, width=2.2 cm; slot height=1.1 cm). The mixtures placed in the slots were then pressed hard with a suitably sized flat metal bar to generate even bar surfaces. 16 bars from each binder were made in this fashion. The resulting bars were then cured at 200° C. for 1 h. After cooling to room temperature, the bars were carefully taken out of the containers. Five of the bars were aged in a water bath at 80° C. for 3 h.

After drying for 1-2 days, the aged bars as well as five unaged bars were broken in a 3 point bending test (test speed: 10.0 mm/min; rupture level: 50%; nominal strength: 30 N/mm²; support distance: 40 mm; max deflection 20 mm; nominal e-module 10000 N/mm²) on a Bent Tram machine to investigate their mechanical strengths. The bars were placed with the “top face” up (i.e. the face with the dimensions length=5.6 cm, width=2.5 cm) in the machine.

Loss of Ignition (LOI) of Bars

The loss of ignition (LOI) of bars was measured in small tin foil containers by treatment at 580° C. For each measurement, a tin foil container was first heat-treated at 580° C. for 15 minutes to remove all organics. The tin foil container was allowed to cool to ambient temperature, and was then weighed. Four bars (usually after being broken in the 3 point bending test) were placed into the tin foil container and the ensemble was weighed. The tin foil container containing bars was then heat-treated at 580° C. for 30 minutes, allowed to cool to ambient temperature, and finally weighed again. The LOI was then calculated using the following formula:

${L\; O\; I\mspace{14mu} (\%)} = {\frac{\begin{matrix} {{{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {before}\mspace{14mu} {heat}\mspace{14mu} {treatment}\mspace{14mu} (g)} -} \\ {{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {after}\mspace{14mu} {heat}\mspace{14mu} {treatment}\mspace{14mu} (g)} \end{matrix}}{{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {before}\mspace{14mu} {heat}\mspace{14mu} {treatment}\mspace{14mu} (g)} \times 100\%}$

Water Absorption Measurements

The water absorption of the binders was measured by weighing three bars and then submerging the bars in water (approx. 250 mL) in a beaker (565 mL, bottom Ø=9.5 cm; top Ø=10.5 cm; height=7.5 cm) for 3 h or 24 h. The bars were placed next to each other on the bottom of the beaker with the “top face” down (i.e. the face with the dimensions length=5.6 cm, width=2.5 cm). After the designated amount of time, the bars were lifted up one by one and allowed to drip off for one minute. The bars were held (gently) with the length side almost vertical so that the droplets would drip from a corner of the bar. The bars were then weighed and the water absorption was calculated using the following formula:

${{Waterabs}.\mspace{11mu} (\%)} = {\frac{\begin{matrix} {{{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {after}\mspace{14mu} {water}\mspace{14mu} {treatment}\mspace{14mu} (g)} -} \\ {{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {before}\mspace{14mu} {water}\mspace{14mu} {treatment}\mspace{14mu} (g)} \end{matrix}}{{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {before}\mspace{14mu} {water}\mspace{14mu} {treatment}\mspace{11mu} (g)} \times 100\%}$

Reference Binder Compositions from the Prior Art

Binder Example, Reference Binder A (Phenol-Formaldehyde Resin Modified with Urea, a PUF-Resol)

A phenol-formaldehyde resin is prepared by reacting 37% aq. formaldehyde (606 g) and phenol (189 g) in the presence of 46% aq. potassium hydroxide (25.5 g) at a reaction temperature of 84° C. preceded by a heating rate of approximately 1° C. per minute. The reaction is continued at 84° C. until the acid tolerance of the resin is 4 and most of the phenol is converted. Urea (241 g) is then added and the mixture is cooled.

The acid tolerance (AT) expresses the number of times a given volume of a binder can be diluted with acid without the mixture becoming cloudy (the binder precipitates). Sulfuric acid is used to determine the stop criterion in a binder production and an acid tolerance lower than 4 indicates the end of the binder reaction. To measure the AT, a titrant is produced from diluting 2.5 mL conc. sulfuric acid (>99%) with 1 L ion exchanged water. 5 mL of the binder to be investigated is then titrated at room temperature with this titrant while keeping the binder in motion by manually shaking it; if preferred, use a magnetic stirrer and a magnetic stick. Titration is continued until a slight cloud appears in the binder, which does not disappear when the binder is shaken.

The acid tolerance (AT) is calculated by dividing the amount of acid used for the titration (mL) with the amount of sample (mL):

AT=(Used titration volume (mL))/(Sample volume (mL))

Using the urea-modified phenol-formaldehyde resin obtained, a binder is made by addition of 25% aq. ammonia (90 mL) and ammonium sulfate (13.2 g) followed by water (1.30 kg). The binder solids were then measured as described above and the mixture was diluted with the required amount of water and silane (Momentive VS-142) for mechanical strength studies (15% binder solids solution, 0.5% silane of binder solids).

Test Methods for Binder Compositions According to the Present Invention and Reference Binders

The following properties were determined for the binders according the present invention and reference binders.

Reagents

Gelatines (Speisegelatine, type A, porcine, 120 and 180 bloom) were obtained from Gelita AG. Tannorouge chestnut tree tannin was obtained from Brouwland bvba. Coconut oil, hemp oil, olive oil, rapeseed oil and sunflower oil were obtained from Urtekram International A/S. Linseed oil was obtained from Borup Kemi I/S. Tung oil and all other components were obtained from Sigma-Aldrich. Unless stated otherwise, these components were assumed completely pure and anhydrous.

Binder Component Solids Content—Definition

The content of each of the components in a given binder solution before curing is based on the anhydrous mass of the components. The following formula can be used:

${{Binder}\mspace{14mu} {component}\mspace{14mu} {solids}\mspace{14mu} {content}\mspace{14mu} (\%)} = {\frac{\begin{matrix} {{{binder}\mspace{14mu} {component}\mspace{14mu} A\mspace{14mu} {solids}\mspace{14mu} (g)} +} \\ {{{binder}\mspace{14mu} {component}\mspace{14mu} B\mspace{14mu} {solids}\mspace{14mu} (g)} + \ldots} \end{matrix}}{{total}\mspace{14mu} {weight}\mspace{14mu} {of}\mspace{14mu} {mixture}\mspace{14mu} (g)} \times 100\%}$

Mechanical Strength Studies (Bar Tests)—Procedure

The mechanical strength of the binders was tested in a bar test. For each binder, 16-20 bars were manufactured from a mixture of the binder and stone wool shots from the stone wool spinning production. The shots are particles which have the same melt composition as the stone wool fibers, and the shots are normally considered a waste product from the spinning process. The shots used for the bar composition have a size of 0.25-0.50 mm.

A binder solution with approx. 15% binder component solids was obtained as described in the examples below. A sample of the binder solution (16.0 g) was mixed well with shots (80.0 g; pre-heated to 40° C. when used in combination with comparatively fast setting binders). The resulting mixture was then filled into four slots in a heat resistant silicone form for making small bars (4×5 slots per form; slot top dimension: length=5.6 cm, width=2.5 cm; slot bottom dimension: length=5.3 cm, width=2.2 cm; slot height=1.1 cm). During the manufacture of each bar, the mixtures placed in the slots were pressed as required and then evened out with a plastic spatula to generate an even bar surface. 16-20 bars from each binder were made in this fashion. The resulting bars were then cured at room temperature for 1-2 days. The bars were then carefully taken out of the containers, turned upside down and left for a day at room temperature to cure completely. Five of the bars were aged in a water bath at 80° C. for 3 h.

After drying for 1-2 days, the aged bars as well as five unaged bars were broken in a 3 point bending test (test speed: 10.0 mm/min; rupture level: 50%; nominal strength: 30 N/mm²; support distance: 40 mm; max deflection 20 mm; nominal e-module 10000 N/mm²) on a Bent Tram machine to investigate their mechanical strengths. The bars were placed with the “top face” up (i.e. the face with the dimensions length=5.6 cm, width=2.5 cm) in the machine.

Loss of Ignition (LOI) of Bars

The loss of ignition (LOI) of bars was measured in small tin foil containers by treatment at 580° C. For each measurement, a tin foil container was first heat-treated at 580° C. for 15 minutes to remove all organics. The tin foil container was allowed to cool to ambient temperature, and was then weighed. Four bars (usually after being broken in the 3 point bending test) were placed into the tin foil container and the ensemble was weighed. The tin foil container containing bars was then heat-treated at 580° C. for 30 minutes, allowed to cool to ambient temperature, and finally weighed again. The LOI was then calculated using the following formula:

${L\; O\; I\mspace{14mu} (\%)} = {\frac{\begin{matrix} {{{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {before}\mspace{14mu} {heat}\mspace{14mu} {treatment}\mspace{14mu} (g)} -} \\ {{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {after}\mspace{14mu} {heat}\mspace{14mu} {treatment}\mspace{14mu} (g)} \end{matrix}}{{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {before}\mspace{14mu} {heat}\mspace{14mu} {treatment}\mspace{14mu} (g)} \times 100\%}$

Water Absorption Measurements

The water absorption of the binders was measured by weighing three bars and then submerging the bars in water (approx. 250 mL) in a beaker (565 mL, bottom Ø=9.5 cm; top Ø=10.5 cm; height=7.5 cm) for 3 h or 24 h. The bars were placed next to each other on the bottom of the beaker with the “top face” down (i.e. the face with the dimensions length=5.6 cm, width=2.5 cm). After the designated amount of time, the bars were lifted up one by one and allowed to drip off for one minute. The bars were held (gently) with the length side almost vertical so that the droplets would drip from a corner of the bar. The bars were then weighed and the water absorption was calculated using the following formula:

${{Waterabs}.\mspace{11mu} (\%)} = {\frac{\begin{matrix} {{{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {after}\mspace{14mu} {water}\mspace{14mu} {treatment}\mspace{14mu} (g)} -} \\ {{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {before}\mspace{14mu} {water}\mspace{14mu} {treatment}\mspace{14mu} (g)} \end{matrix}}{{Weight}\mspace{14mu} {of}\mspace{14mu} {bars}\mspace{14mu} {before}\mspace{14mu} {water}\mspace{14mu} {treatment}\mspace{11mu} (g)} \times 100\%}$

Binder Compositions According to the Present Invention and Reference Binders

Binder Example, Entry B

To 1M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatin (Speisegelatine, type A, porcine, 120 bloom, 12.0 g) in water (68.0 g) was stirred at 50° C. for approx. 15-30 min until a clear solution was obtained (pH 5.0). 1M NaOH (4.37 g) was then added (pH 9.1) followed by a portion of the above chestnut tree tannin solution (5.40 g; thus efficiently 1.20 g chestnut tree tannin). After stirring for 1-2 minutes further at 50° C., the resulting brown mixture (pH 9.1) was used in the subsequent experiments.

Binder Example, Entry 3

To 1M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatin (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50° C. for approx. 15-30 min until a clear solution was obtained (pH 5.1). 1M NaOH (4.00 g) was added (pH 9.3) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin). Coconut oil (0.65 g) was then added under vigorous stirring. After stirring vigorously for approx. 1 minute at 50° C., the stirring speed was slowed down again and the resulting brown mixture (pH 9.3) was used in the subsequent experiments.

Binder Example, Entry 5

To 1M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatin (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50° C. for approx. 15-30 min until a clear solution was obtained (pH 4.8). 1M NaOH (4.00 g) was added (pH 9.2) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin). Linseed oil (0.65 g) was then added under vigorous stirring. After stirring vigorously for approx. 1 minute at 50° C., the stirring speed was slowed down again and the resulting brown mixture (pH 9.2) was used in the subsequent experiments.

Binder Example, Entry 6

To 1M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatin (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50° C. for approx. 15-30 min until a clear solution was obtained (pH 4.8). 1M NaOH (4.00 g) was added (pH 9.2) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin). Olive oil (0.65 g) was then added under vigorous stirring. After stirring vigorously for approx. 1 minute at 50° C., the stirring speed was slowed down again and the resulting brown mixture (pH 9.1) was used in the subsequent experiments.

Binder Example, Entry 9

To 1M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatin (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50° C. for approx. 15-30 min until a clear solution was obtained (pH 4.8). 1M NaOH (4.00 g) was added (pH 9.3) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin). Tung oil (0.16 g) was then added under vigorous stirring. After stirring vigorously for approx. 1 minute at 50° C., the stirring speed was slowed down again and the resulting brown mixture (pH 9.4) was used in the subsequent experiments.

Binder Example, Entry 11

To 1M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatin (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50° C. for approx. 15-30 min until a clear solution was obtained (pH 5.0). 1M NaOH (4.00 g) was added (pH 9.1) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin). Tung oil (1.13 g) was then added under vigorous stirring. After stirring vigorously for approx. 1 minute at 50° C., the stirring speed was slowed down again and the resulting brown mixture (pH 9.1) was used in the subsequent experiments.

Binder Example, Entry C

To 1M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatin (Speisegelatine, type A, porcine, 180 bloom, 12.0 g) in water (68.0 g) was stirred at 50° C. for approx. 15-30 min until a clear solution was obtained (pH 5.0). 1M NaOH (3.81 g) was then added (pH 9.1) followed by a portion of the above chestnut tree tannin solution (5.40 g; thus efficiently 1.20 g chestnut tree tannin). After stirring for 1-2 minutes further at 50° C., the resulting brown mixture (pH 9.3) was used in the subsequent experiments.

Binder Example, Entry 12

To 1M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatin (Speisegelatine, type A, porcine, 180 bloom, 10.0 g) in water (56.7 g) was stirred at 50° C. for approx. 15-30 min until a clear solution was obtained (pH 5.0). 1M NaOH (3.28 g) was added (pH 9.2) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin). Tung oil (0.65 g) was then added under vigorous stirring. After stirring vigorously for approx. 1 minute at 50° C., the stirring speed was slowed down again and the resulting brown mixture (pH 9.1) was used in the subsequent experiments.

TABLE 1-1 Binder composition according to the prior art Example A Binder properties Binder solids (%) 15.0 Reaction loss (%) 28.5 pH 9.6 Bar curing conditions Temperature (° C./1 h) 200 Bar properties Mechanical strength, unaged (kN) 0.39 Mechanical strength, aged (kN) 0.28 LOI, unaged (%) 2.8 LOI, aged (%) 2.8 Water absorption, 3 h (%) 4 Water absorption, 24 h (%) 8

TABLE 1-2 Protein, crosslinker, mineral oil or fatty acid ester of glycerol Example B 1 2 3 4 5 6 Binder composition Protein (%-wt.) Gelatin, Speisegelatine, 120 bloom 100 100 100 100 100 100 100 Gelatin, Speisegelatine, 180 bloom — — — — — — — Crosslinker (%-wt.) ^([a]) Chestnut tree tannin 10 10 10 10 10 10 10 Fatty acid ester of glycerol (%-wt.) ^([a]) Mineral oil — 1.6 6.5 — — — — Coconut oil (iodine number 7 to 10) — — — 6.5 — — — Hemp oil (iodine number 140 to 170) — — — — 6.5 — — Linseed oil (iodine number 136 to 178) — — — — — 6.5 — Olive oil (iodine number 80 to 88) — — — — — — 6.5 Base (%-wt.) ^([b]) Sodium hydroxide 2.5 2.6 2.5 2.5 2.5 2.5 2.5 Binder mixing and bar manufacture Binder component solids content (%) 15.1 15.2 15.7 15.7 15.7 15.7 15.7 pH of binder mixture 9.1 9.1 9.1 9.3 9.1 9.2 9.1 Curing temperature (° C.) rt rt rt rt rt rt rt Bar properties Mechanical strength, unaged (kN) 0.22 0.19 0.18 0.31 0.31 0.34 0.34 Mechanical strength, aged (kN) 0.17 0.12 0.12 0.25 0.24 0.30 0.28 LOI, unaged (%) 2.9 2.9 2.9 3.0 3.0 3.0 3.0 LOI, water bath aged (%) 2.6 2.6 2.7 2.8 2.8 2.8 2.8 Water absorption, 3 h (%) 16 18 16 10 10 9 10 Water absorption, 24 h (%) 31 31 32 23 24 23 22 ^([a]) Of protein. ^([b]) Of protein + crosslinker.

TABLE 1-3 Protein, crosslinker, fatty acid ester of glycerol Example B 7 8 9 10 11 C 12 Binder composition Protein (%-wt.) Gelatin, Speisegelatine, 120 bloom 100 100 100 100 100 100 — — Gelatin, Speisegelatine, 180 bloom — — — — — — 100 100 Crosslinker (%-wt.) ^([a]) Chestnut tree tannin 10 10 10 10 10 10 10 10 Fatty acid ester of glycerol (%-wt.) ^([a]) Rapeseed oil (iodine number 94 to 120) — 6.5 — — — — — — Sunflower oil (iodine number 118 to 144) — — 6.5 — — — — — Tung oil (iodine number 163 to 173) — — — 1.6 6.5 11.3 — 6.5 Base (%-wt.) ^([b]) Sodium hydroxide 2.5 2.5 2.5 2.6 2.5 2.4 2.3 2.2 Binder mixing and bar manufacture Binder component solids content (%) 15.1 15.7 15.7 15.2 15.7 16.3 15.1 15.9 pH of binder mixture 9.1 9.1 9.2 9.4 9.1 9.1 9.3 9.1 Curing temperature (° C.) rt rt rt rt rt rt rt rt Bar properties Mechanical strength, unaged (kN) 0.22 0.28 0.26 0.29 0.32 0.28 0.24 0.37 Mechanical strength, aged (kN) 0.17 0.25 0.21 0.22 0.22 0.21 0.17 0.34 LOI, unaged (%) 2.9 2.9 3.0 2.9 3.0 3.1 2.9 3.0 LOI, water bath aged (%) 2.6 2.8 2.8 2.7 2.9 3.0 2.8 2.9 Water absorption, 3 h (%) 16 11 10 11 8 8 13 9 Water absorption, 24 h (%) 31 25 24 24 23 20 25 22 ^([a]) Of protein. ^([b]) Of protein + crosslinker. 

1.-27. (canceled)
 28. A binder composition for mineral fibers, wherein the composition is formaldehyde-free and comprises (i) at least one phenol and/or quinone containing compound, (ii) at least one protein, and (iii) at least one fatty acid ester of glycerol.
 29. The binder composition of claim 28, wherein (i) comprises a phenol containing compound.
 30. The binder composition of claim 28, wherein (i) comprises one or more of a hydroxybenzoic acid, a hydroxybenzoic aldehyde, a hydroxyacetophenone, a hydroxyphenylacetic acid, a cinnamic acid, a cinnamic acid ester, a cinnamyl aldehyde, a cinnamyl alcohol, a coumarin, an isocoumarin, a chromone, a flavonoid, a chalcone, a dihydrochalcone, an aurone, a flavanone, a flavanonol, a flavan, a leucoanthocyanidine, a flavan-3-ol, a flavone, an anthocyanidine, a deoxyanthocyanidine, an anthocyanine, a biflavonyl, a benzophenone, a xanthone, a stilbene, a benzoquinone, a naphthoquinone, an anthraquinone, a betacyanine, a polyphenol, a polyhydroxyphenol, a lignan, a neolignan (dimers or oligomers formed by coupling of monolignols), a lignin, a tannin, a condensed tannin (proanthocyanidine), a hydrolysable tannin, a gallotannin, an ellagitannin, a complex tannin, tannic acid, a phlobabene, a lawsone.
 31. The binder composition of claim 28, wherein (i) comprises one or more of tannic acid, a condensed tannin (proanthocyanidine), a hydrolysable tannin, a gallotannin, an ellagitannin, a complex tannin, and a tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups.
 32. The binder composition of claim 28, wherein (i) comprises one or more synthetic or semisynthetic molecules which contain a phenol, a polyphenol and/or a quinone.
 33. The binder composition of claim 32, wherein (i) comprises one or more of a protein, a peptide, a peptoid, an arylopeptoid, and a polystyrene modified with phenol and/or quinone containing side chains.
 34. The binder composition of claim 33, wherein (i) comprises a dendrimer comprising phenol and/or quinone containing side chains.
 35. The binder composition of claim 28, wherein (ii) comprises at least one protein from animal sources.
 36. The binder composition of claim 28, wherein (ii) comprises at least one protein from vegetable sources.
 37. The binder composition of claim 28, wherein (i) comprises at least one tannin in a concentration of 1-70 wt. % based on dry protein.
 38. The binder composition of claim 28, wherein a mass ratio of (lysine+cysteine) in (ii) to (phenol+quinone) in (i) is from 1:5.78 to 1:0.08.
 39. The binder composition of claim 28, wherein (iii) is present in the form of a plant oil and/or an animal oil.
 40. The binder composition of claim 28, wherein (iii) is present as one or more of linseed oil, olive oil, tung oil, coconut oil, hemp oil, rapeseed oil, and sunflower oil.
 41. The binder composition of claim 28, wherein (iii) comprises a plant oil and/or animal oil having an iodine number of ≥75 and/or an iodine number of ≤100.
 42. The binder composition of claim 28, wherein (iii) is present in a concentration of from 0.5 wt.-% to 40 wt.-%, based on dry protein.
 43. The binder composition of claim 28, wherein the composition further comprises one or more additives selected from oxidants, metal ions, and pH-adjusters.
 44. The binder composition of claim 28, wherein the composition has a pH of higher than
 7. 45. The binder composition of claim 28, wherein composition further comprises at least one linker comprising amine and/or thiol groups.
 46. A mineral wool product, wherein the product comprises mineral fibers bonded by the binder composition of claim
 28. 47. A method of producing a mineral wool product, wherein the method comprises contacting mineral fibers with the binder composition of claim 28 and curing the binder composition. 